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I have fished a reservoir just outside Edinburgh for over 15 years and this year we have experienced a massive algal bloom for the first time. The algae reaches from the bottom of the loch right up to the surface and covers everything in its path. I know these images are not the best but any advice on cause or prevention.
Does it stink? It looks like some kind of sewage pollution.
Had it last year in a hill loch I fish. No sewage or any form of human intervention there. I assumed, perhaps wrongly, very low water and hot weather had caused it. It has not reappeared this year.
No i don't recall it being smelly, We are high up in the Pentland hills so not sure where a source of sewage would come from. The algae is much greener that it looks in the photos.
It was the colour that worried me, it may turn brown as it dies off as the water cools down.
I've noticed this on a few lochs this year. I assumed it was down to the extended dry period we've had.
Extended dry weather can often reduce algae as there is less nutrient run off from surrounding fields. It depends on the loch I guess.
It is Filamentous Algae.
http://www.newtechbio.com/wiki/index.php?title=Filamentous_Algae
its odd that "arawa" mentioned low water as the reservoir was manually drawn down several feet at the start of year for some work to be carried out.
This reduction in water level has happened before but never resulted in the bloom we seem to have just now.
Quote from: Fishtales on October 02, 2021, 12:57:07 PM
It is Filamentous Algae.
http://www.newtechbio.com/wiki/index.php?title=Filamentous_Algae
Good find Sandy. :D
Quote from: smackinnon on October 02, 2021, 01:03:41 PM
its odd that "arawa" mentioned low water as the reservoir was manually drawn down several feet at the start of year for some work to be carried out.
This reduction in water level has happened before but never resulted in the bloom we seem to have just now.
I thought the low water might be relevant (to my loch) because it left large areas of very shallow water that in the hot weather became very warm indeed.
Our two local lochs, Rescobie and Balgavies, (and various swamp ponds we fished when we were kids) have a real algae problem and even worse Canadian Pond weed. Back in the day there was none of that weed, where the hell did tat come from? Keptie Pond in Arbroath gets choked with it too.
Quote from: arawa on October 02, 2021, 01:43:16 PM
I thought the low water might be relevant (to my loch) because it left large areas of very shallow water that in the hot weather became very warm indeed.
It's just weird. After a very dry summer in 2003 Rescobie Loch was gin clear in October when we fished it. I could see the bottom out in the middle, never seen that before and had not realised how shallow it was. There were masses of huge freshwater mussels in clear view.
Nice one Sandy, well found.
Just another example of the benefit of such forums, the wealth on information and knowledge is amazing.